ngx.shared.DICT.incr optional expire argument

README.markdown

@@ -3055,6 +3055,7 @@ Nginx API for Lua
 * [ngx.shared.DICT.add](#ngxshareddictadd)
 * [ngx.shared.DICT.safe_add](#ngxshareddictsafe_add)
 * [ngx.shared.DICT.replace](#ngxshareddictreplace)
+* [ngx.shared.DICT.cas](#ngxshareddictcas)
 * [ngx.shared.DICT.delete](#ngxshareddictdelete)
 * [ngx.shared.DICT.incr](#ngxshareddictincr)
 * [ngx.shared.DICT.lpush](#ngxshareddictlpush)
@@ -6054,6 +6055,7 @@ The resulting object `dict` has the following methods:
 * [add](#ngxshareddictadd)
 * [safe_add](#ngxshareddictsafe_add)
 * [replace](#ngxshareddictreplace)
+* [cas](#ngxshareddictcas)
 * [delete](#ngxshareddictdelete)
 * [incr](#ngxshareddictincr)
 * [lpush](#ngxshareddictlpush)
@@ -6277,6 +6279,62 @@ See also [ngx.shared.DICT](#ngxshareddict).
 
 [Back to TOC](#nginx-api-for-lua)
 
+ngx.shared.DICT.cas
+-------------------
+**syntax:** *success, err, forcible, current_value?, current_flags? = ngx.shared.DICT:cas(key, value, exptime, flags, old_value, old_flags?)*
+
+**context:** *init_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, log_by_lua*, ngx.timer.*, balancer_by_lua*, certificate_by_lua**
+
+Just like the [replace](#ngxshareddictreplace) method, but only stores the key-value pair into the dictionary [ngx.shared.DICT](#ngxshareddict) if and only if the `old_value` argument and `old_flags` argument *do* match the value and flags in the dictionary [ngx.shared.DICT](#ngxshareddict).
+
+The `old_value` argument can be `nil` only when `old_flags` argument is specified, in which case only `flags` will be checked.
+
+If `old_flags` argument is not specified, only `value` will be checked.
+
+The optional `old_flags` argument can be `nil`, and it means `0`.
+
+If they do *not* match, the `success` return value will be `false` and the `err` return value will be `"not matched"`. The `current_value` return value and `current_flags` return value will be the current `value` and current `flags` in the dictionary [ngx.shared.DICT](#ngxshareddict), just like [get](#ngxshareddictget) does.
+
+This function is often used to avoid race condition between [get](#ngxshareddictget) and [set](#ngxshareddictset) across multipe nginx worker processes, and below is an example:
+
+```lua
+
+ local cats = ngx.shared.cats
+ cats:set("foo", 1, 1)
+
+ local old_value, old_flags = cats:get("foo")
+
+ while true do
+     local newvalue = calculate(old_value) -- some logic
+     local newflags = (old_flags or 0) + 1
+
+     local success, err, forcibly, current_value, current_flags
+         = cats:cas("foo", newvalue, 0, newflags, old_value, old_flags)
+
+     if success then
+         break
+
+     elseif err == "not matched" then
+         old_value = current_value
+         old_flags = current_flags
+
+     elseif err == "not found" then
+         -- add or some other handle
+         cats:add("foo", newvalue, 0, newflags)
+         break
+
+     else
+         -- "no memory" or some other error
+         -- just log or some other handle
+         break
+     end
+ end
+```
+
+See also [ngx.shared.DICT](#ngxshareddict).
+
+[Back to TOC](#nginx-api-for-lua)
+
 ngx.shared.DICT.delete
 ----------------------
 **syntax:** *ngx.shared.DICT:delete(key)*

doc/HttpLuaModule.wiki

@@ -5067,6 +5067,7 @@ The resulting object <code>dict</code> has the following methods:
 * [[#ngx.shared.DICT.add|add]]
 * [[#ngx.shared.DICT.safe_add|safe_add]]
 * [[#ngx.shared.DICT.replace|replace]]
+* [[#ngx.shared.DICT.cas|cas]]
 * [[#ngx.shared.DICT.delete|delete]]
 * [[#ngx.shared.DICT.incr|incr]]
 * [[#ngx.shared.DICT.lpush|lpush]]
@@ -5261,6 +5262,58 @@ This feature was first introduced in the <code>v0.3.1rc22</code> release.
 
 See also [[#ngx.shared.DICT|ngx.shared.DICT]].
 
+== ngx.shared.DICT.cas ==
+'''syntax:''' ''success, err, forcible, current_value?, current_flags? = ngx.shared.DICT:cas(key, value, exptime, flags, old_value, old_flags?)''
+
+'''context:''' ''init_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, log_by_lua*, ngx.timer.*, balancer_by_lua*, certificate_by_lua*''
+
+Just like the [[#ngx.shared.DICT.replace|replace]] method, but only stores the key-value pair into the dictionary [[#ngx.shared.DICT|ngx.shared.DICT]] if and only if the <code>old_value</code> argument and <code>old_flags</code> argument ''do'' match the value and flags in the dictionary [[#ngx.shared.DICT|ngx.shared.DICT]].
+
+The <code>old_value</code> argument can be <code>nil</code> only when <code>old_flags</code> argument is specified, in which case only <code>flags</code> will be checked.
+
+If <code>old_flags</code> argument is not specified, only <code>value</code> will be checked.
+
+The optional <code>old_flags</code> argument can be <code>nil</code>, and it means <code>0</code>.
+
+If they do ''not'' match, the <code>success</code> return value will be <code>false</code> and the <code>err</code> return value will be <code>"not matched"</code>. The <code>current_value</code> return value and <code>current_flags</code> return value will be the current <code>value</code> and current <code>flags</code> in the dictionary [[#ngx.shared.DICT|ngx.shared.DICT]], just like [[#ngx.shared.DICT.get|get]] does.
+
+This function is often used to avoid race condition between [[#ngx.shared.DICT.get|get]] and [[#ngx.shared.DICT.set|set]] across multipe nginx worker processes, and below is an example:
+
+<geshi lang="lua">
+    local cats = ngx.shared.cats
+    cats:set("foo", 1, 1)
+
+    local old_value, old_flags = cats:get("foo")
+
+    while true do
+        local newvalue = calculate(old_value) -- some logic
+        local newflags = (old_flags or 0) + 1
+
+        local success, err, forcibly, current_value, current_flags
+            = cats:cas("foo", newvalue, 0, newflags, old_value, old_flags)
+
+        if success then
+            break
+
+        elseif err == "not matched" then
+            old_value = current_value
+            old_flags = current_flags
+
+        elseif err == "not found" then
+            -- add or some other handle
+            cats:add("foo", newvalue, 0, newflags)
+            break
+
+        else
+            -- "no memory" or some other error
+            -- just log or some other handle
+            break
+        end
+    end
+</geshi>
+
+See also [[#ngx.shared.DICT|ngx.shared.DICT]].
+
 == ngx.shared.DICT.delete ==
 '''syntax:''' ''ngx.shared.DICT:delete(key)''
 
@@ -5275,7 +5328,7 @@ This feature was first introduced in the <code>v0.3.1rc22</code> release.
 See also [[#ngx.shared.DICT|ngx.shared.DICT]].
 
 == ngx.shared.DICT.incr ==
-'''syntax:''' ''newval, err, forcible? = ngx.shared.DICT:incr(key, value, init?)''
+'''syntax:''' ''newval, err, forcible? = ngx.shared.DICT:incr(key, value, init?, exptime?)''
 
 '''context:''' ''init_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, log_by_lua*, ngx.timer.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*''
 

src/ngx_http_lua_control.c

@@ -212,11 +212,13 @@ ngx_http_lua_ngx_redirect(lua_State *L)
 
         if (rc != NGX_HTTP_MOVED_TEMPORARILY
             && rc != NGX_HTTP_MOVED_PERMANENTLY
-            && rc != NGX_HTTP_TEMPORARY_REDIRECT)
+            && rc != NGX_HTTP_TEMPORARY_REDIRECT
+            && rc != NGX_HTTP_SEE_OTHER)
         {
             return luaL_error(L, "only ngx.HTTP_MOVED_TEMPORARILY, "
                               "ngx.HTTP_MOVED_PERMANENTLY, and "
-                              "ngx.HTTP_TEMPORARY_REDIRECT are allowed");
+                              "ngx.HTTP_TEMPORARY_REDIRECT, and"
+                              "ngx.HTTP_SEE_OTHER are allowed");
         }
 
     } else {